Through the past decade-plus, though, there has been at least one constant in the running back world: Frank Gore.

Since coming into the NFL in 2005, no player has rushed for more yards than Gore. His 14,026 yards are 1,750 more than his closest challenger: Adrian Peterson. On the all-time rushing leaders list, Gore is currently in fifth place, and he needs 75 yards to overtake Curtis Martin for fourth place.

But after spending the last three seasons with the Indianapolis Colts, Gore will be looking for those yards, and no doubt a few more, on a new team.

As good a player as Gore has been throughout his career, it is fair to question just how much he has left in the tank and also how good a fit he will be with the Dolphins in 2018.

More Name than Game

While Gore certainly brings a veteran presence with him to Miami, perhaps his most efficient days are behind him.

Gore certainly had plenty of volume in 2017, as his 261 carries were the most among running backs on a Colts team that had the seventh-lowest pass-to-run ratio in the league (1.20). However, according to numberFire's Net Expected Points (NEP) metric, Gore was among the least efficient running backs in the NFL.

NEP is a metric that describes the contribution a player makes to his team’s chances of scoring. By adding down-and-distance value to the box score production, we can see how each play influences the outcome of games. For more info on NEP, check out our glossary.

Of the 18 running backs to have a minimum of 200 rushing attempts last season, Gore ranked 13th in Rushing NEP per play (-0.05). Among this sample size, the average was -0.02.

Gore's Rushing Success Rate, the percentage of plays that positively impact a player's NEP, was 37.16%. Again, this was below the average (38.17%) and ranked 10th out of 18.

In 2016, Gore performed at a league-average level on a per-play basis, with a Rushing NEP per play of -0.02. But as for performing above the midpoint at his position, you have to go all the way back to the 2012 season for the last time Gore's Rushing NEP per play exceeded the league average. Further, after 10 consecutive seasons to start his career with at least a 4.1 yards per attempt average, Gore has not been able to top 3.9 in any of his last three campaigns.

But team context is important for running backs, and Gore did outperform his Colts teammates in 2017. For this comparison, we will exclude fumbles, which can swing Rushing NEP quite substantially considering that the average running back carry loses expected points, via our models.

In 2017, non-Gore Colts running backs combined for a Rushing NEP per carry of -0.06 and a 35.25% Rushing Success Rate, whereas Gore's marks were -0.05 and 36.78%, respectively.

However, in 2016, Gore's teammates produced 0.05 Rushing NEP per carry on a 45.07% Success Rate, while Gore's marks were -0.01 and 40.84%, respectively.

Less-Than-Ideal Surroundings

It is one thing to acknowledge that Gore may not be the player he once was, but it is vital to remember that his new team is not exactly an ideal landing spot for a volume-dependent running back. The Dolphins had the highest pass-to-run ratio in the NFL last season, at 1.76.

Regardless of whether they were running or throwing, on a per-play basis, their offense was among the worst in the NFL.

With -0.09 Adjusted NEP per play, the Dolphins ranked 32nd in the NFL in 2017. They were 30th in Adjusted Passing NEP per play and in Adjusted Rushing NEP per play. Only the Detroit Lions, Cincinnati Bengals and Arizona Cardinals had fewer rushing yards than the Dolphins.

This lack of efficient production flew somewhat in the face of the track record Dolphins head coach Adam Gase had established for himself as a coach of running backs. In fact, 2017 was the first time in his career as either an offensive coordinator or head coach that one of his running backs did not produce at or above a league-average level in terms of rushing NEP per play (with a minimum of 100 rush attempts).

As well as seriously efficient production from Ajayi in 2016, Gase also coached Knowshon Moreno to 0.07 Rushing NEP per carry in 2013 against a league average of -0.03, and C.J. Anderson had 0.10 Rushing NEP per carry in 2014. In that season, the average for running backs was -0.03.

But the Dolphins are still being linked with quarterbacks in the upcoming draft. Plus, on Friday they signed free agent Brock Osweiler...but you can take from that what you will.

The Dolphins traded wide receiver Jarvis Landry to the Cleveland Browns earlier this month, waving goodbye to a huge chunk of their offensive production over the last few year. Landry's 400 receptions since 2014 made up 27.6% of all passes caught by Dolphins players in that span.

In his wake, the Dolphins have the speedy Kenny Stills, who had the 20th highest Target NEP per target among the 27 wide receivers to see 100 targets last season (0.18), as well as former first-round draft pick DeVante Parker. Parker has averaged a disappointing 44.4 receiving yards per game in the first three seasons of his career. Parker recorded -0.03 Target NEP per target last season, 74th among the 85 wide receivers with 50 or more targets.

If ever a team could do with leaning on their ground game to hold up their offense, it's the 2018 Miami Dolphins. But putting a team on the back of a player at such an advanced age as Gore (he'll be 35 when the season starts) doesn't seem to me to be a wise solution.

Fantasy Outlook

Assuming the Dolphins don't look to keep bringing in running backs, it would appear that Gore will be twinned with Kenyan Drake. Drake, on a per-play basis, wasn't that hot himself in 2017, with his -0.04 Rushing NEP per carry ranking 21st out of 47 with at least 100 rushing attempts.

But he did average 5.4 yards per carry on the woeful Dolphins offense last season, and he also offers something in the receiving game that Gore just can't -- or hasn't shown -- at this stage of his career. Drake had three games in 2017 in which he had at least five receptions. You have to go back to Week 7 of the 2016 season for the last game in which Gore had five or more.

At this point in the offseason, Drake offers some small appeal, especially in PPR formats, if it is to be a true timeshare, yet it is very difficult for me to foresee a situation where I'd be confident in wheeling out Gore in my lineups given his current skill level and that of his mates.

The Dolphins, as of late March, have all the hallmarks of being a bad football team in 2018. Old running backs on bad football teams do not ideal fantasy players make.

Gore has been a tremendous servant to the NFL, and the game has been richer for his presence in it. But at this stage of the game, given his age and the mess of an offense he has landed on, I can't help but think that my fantasy teams will be richer for his absence.